Merge tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux

Pull drm updates from Dave Airlie:
 "Core:
   - Fence destaging work
   - DRIVER_LEGACY to split off legacy drm drivers
   - drm_mm refactoring
   - Splitting drm_crtc.c into chunks and documenting better
   - Display info fixes
   - rbtree support for prime buffer lookup
   - Simple VGA DAC driver

  Panel:
   - Add Nexus 7 panel
   - More simple panels

  i915:
   - Refactoring GEM naming
   - Refactored vma/active tracking
   - Lockless request lookups
   - Better stolen memory support
   - FBC fixes
   - SKL watermark fixes
   - VGPU improvements
   - dma-buf fencing support
   - Better DP dongle support

  amdgpu:
   - Powerplay for Iceland asics
   - Improved GPU reset support
   - UVD/VEC powergating support for CZ/ST
   - Preinitialised VRAM buffer support
   - Virtual display support
   - Initial SI support
   - GTT rework
   - PCI shutdown callback support
   - HPD IRQ storm fixes

  amdkfd:
   - bugfixes

  tilcdc:
   - Atomic modesetting support

  mediatek:
   - AAL + GAMMA engine support
   - Hook up gamma LUT
   - Temporal dithering support

  imx:
   - Pixel clock from devicetree
   - drm bridge support for LVDS bridges
   - active plane reconfiguration
   - VDIC deinterlacer support
   - Frame synchronisation unit support
   - Color space conversion support

  analogix:
   - PSR support
   - Better panel on/off support

  rockchip:
   - rk3399 vop/crtc support
   - PSR support

  vc4:
   - Interlaced vblank timing
   - 3D rendering CPU overhead reduction
   - HDMI output fixes

  tda998x:
   - HDMI audio ASoC support

  sunxi:
   - Allwinner A33 support
   - better TCON support

  msm:
   - DT binding cleanups
   - Explicit fence-fd support

  sti:
   - remove sti415/416 support

  etnaviv:
   - MMUv2 refactoring
   - GC3000 support

  exynos:
   - Refactoring HDMI DCC/PHY
   - G2D pm regression fix
   - Page fault issues with wait for vblank

  There is no nouveau work in this tree, as Ben didn't get a pull
  request in, and he was fighting moving to atomic and adding mst
  support, so maybe best it waits for a cycle"

* tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux: (1412 commits)
  drm/crtc: constify drm_crtc_index parameter
  drm/i915: Fix conflict resolution from backmerge of v4.8-rc8 to drm-next
  drm/i915/guc: Unwind GuC workqueue reservation if request construction fails
  drm/i915: Reset the breadcrumbs IRQ more carefully
  drm/i915: Force relocations via cpu if we run out of idle aperture
  drm/i915: Distinguish last emitted request from last submitted request
  drm/i915: Allow DP to work w/o EDID
  drm/i915: Move long hpd handling into the hotplug work
  drm/i915/execlists: Reinitialise context image after GPU hang
  drm/i915: Use correct index for backtracking HUNG semaphores
  drm/i915: Unalias obj->phys_handle and obj->userptr
  drm/i915: Just clear the mmiodebug before a register access
  drm/i915/gen9: only add the planes actually affected by ddb changes
  drm/i915: Allow PCH DPLL sharing regardless of DPLL_SDVO_HIGH_SPEED
  drm/i915/bxt: Fix HDMI DPLL configuration
  drm/i915/gen9: fix the watermark res_blocks value
  drm/i915/gen9: fix plane_blocks_per_line on watermarks calculations
  drm/i915/gen9: minimum scanlines for Y tile is not always 4
  drm/i915/gen9: fix the WaWmMemoryReadLatency implementation
  drm/i915/kbl: KBL also needs to run the SAGV code
  ...

1 files changed, 689 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h
new file mode 100644
index 000000000000..974bd7bcc801
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gem_request.h
@@ -0,0 +1,689 @@
+/*
+ * Copyright © 2008-2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef I915_GEM_REQUEST_H
+#define I915_GEM_REQUEST_H
+
+#include <linux/fence.h>
+
+#include "i915_gem.h"
+#include "i915_sw_fence.h"
+
+struct intel_wait {
+	struct rb_node node;
+	struct task_struct *tsk;
+	u32 seqno;
+};
+
+struct intel_signal_node {
+	struct rb_node node;
+	struct intel_wait wait;
+};
+
+/**
+ * Request queue structure.
+ *
+ * The request queue allows us to note sequence numbers that have been emitted
+ * and may be associated with active buffers to be retired.
+ *
+ * By keeping this list, we can avoid having to do questionable sequence
+ * number comparisons on buffer last_read|write_seqno. It also allows an
+ * emission time to be associated with the request for tracking how far ahead
+ * of the GPU the submission is.
+ *
+ * When modifying this structure be very aware that we perform a lockless
+ * RCU lookup of it that may race against reallocation of the struct
+ * from the slab freelist. We intentionally do not zero the structure on
+ * allocation so that the lookup can use the dangling pointers (and is
+ * cogniscent that those pointers may be wrong). Instead, everything that
+ * needs to be initialised must be done so explicitly.
+ *
+ * The requests are reference counted.
+ */
+struct drm_i915_gem_request {
+	struct fence fence;
+	spinlock_t lock;
+
+	/** On Which ring this request was generated */
+	struct drm_i915_private *i915;
+
+	/**
+	 * Context and ring buffer related to this request
+	 * Contexts are refcounted, so when this request is associated with a
+	 * context, we must increment the context's refcount, to guarantee that
+	 * it persists while any request is linked to it. Requests themselves
+	 * are also refcounted, so the request will only be freed when the last
+	 * reference to it is dismissed, and the code in
+	 * i915_gem_request_free() will then decrement the refcount on the
+	 * context.
+	 */
+	struct i915_gem_context *ctx;
+	struct intel_engine_cs *engine;
+	struct intel_ring *ring;
+	struct intel_signal_node signaling;
+
+	struct i915_sw_fence submit;
+	wait_queue_t submitq;
+
+	/** GEM sequence number associated with the previous request,
+	 * when the HWS breadcrumb is equal to this the GPU is processing
+	 * this request.
+	 */
+	u32 previous_seqno;
+
+	/** Position in the ring of the start of the request */
+	u32 head;
+
+	/**
+	 * Position in the ring of the start of the postfix.
+	 * This is required to calculate the maximum available ring space
+	 * without overwriting the postfix.
+	 */
+	u32 postfix;
+
+	/** Position in the ring of the end of the whole request */
+	u32 tail;
+
+	/** Position in the ring of the end of any workarounds after the tail */
+	u32 wa_tail;
+
+	/** Preallocate space in the ring for the emitting the request */
+	u32 reserved_space;
+
+	/**
+	 * Context related to the previous request.
+	 * As the contexts are accessed by the hardware until the switch is
+	 * completed to a new context, the hardware may still be writing
+	 * to the context object after the breadcrumb is visible. We must
+	 * not unpin/unbind/prune that object whilst still active and so
+	 * we keep the previous context pinned until the following (this)
+	 * request is retired.
+	 */
+	struct i915_gem_context *previous_context;
+
+	/** Batch buffer related to this request if any (used for
+	 * error state dump only).
+	 */
+	struct i915_vma *batch;
+	struct list_head active_list;
+
+	/** Time at which this request was emitted, in jiffies. */
+	unsigned long emitted_jiffies;
+
+	/** engine->request_list entry for this request */
+	struct list_head link;
+
+	/** ring->request_list entry for this request */
+	struct list_head ring_link;
+
+	struct drm_i915_file_private *file_priv;
+	/** file_priv list entry for this request */
+	struct list_head client_list;
+
+	/** Link in the execlist submission queue, guarded by execlist_lock. */
+	struct list_head execlist_link;
+};
+
+extern const struct fence_ops i915_fence_ops;
+
+static inline bool fence_is_i915(struct fence *fence)
+{
+	return fence->ops == &i915_fence_ops;
+}
+
+struct drm_i915_gem_request * __must_check
+i915_gem_request_alloc(struct intel_engine_cs *engine,
+		       struct i915_gem_context *ctx);
+int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
+				   struct drm_file *file);
+void i915_gem_request_retire_upto(struct drm_i915_gem_request *req);
+
+static inline u32
+i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
+{
+	return req ? req->fence.seqno : 0;
+}
+
+static inline struct intel_engine_cs *
+i915_gem_request_get_engine(struct drm_i915_gem_request *req)
+{
+	return req ? req->engine : NULL;
+}
+
+static inline struct drm_i915_gem_request *
+to_request(struct fence *fence)
+{
+	/* We assume that NULL fence/request are interoperable */
+	BUILD_BUG_ON(offsetof(struct drm_i915_gem_request, fence) != 0);
+	GEM_BUG_ON(fence && !fence_is_i915(fence));
+	return container_of(fence, struct drm_i915_gem_request, fence);
+}
+
+static inline struct drm_i915_gem_request *
+i915_gem_request_get(struct drm_i915_gem_request *req)
+{
+	return to_request(fence_get(&req->fence));
+}
+
+static inline struct drm_i915_gem_request *
+i915_gem_request_get_rcu(struct drm_i915_gem_request *req)
+{
+	return to_request(fence_get_rcu(&req->fence));
+}
+
+static inline void
+i915_gem_request_put(struct drm_i915_gem_request *req)
+{
+	fence_put(&req->fence);
+}
+
+static inline void i915_gem_request_assign(struct drm_i915_gem_request **pdst,
+					   struct drm_i915_gem_request *src)
+{
+	if (src)
+		i915_gem_request_get(src);
+
+	if (*pdst)
+		i915_gem_request_put(*pdst);
+
+	*pdst = src;
+}
+
+int
+i915_gem_request_await_object(struct drm_i915_gem_request *to,
+			      struct drm_i915_gem_object *obj,
+			      bool write);
+
+void __i915_add_request(struct drm_i915_gem_request *req, bool flush_caches);
+#define i915_add_request(req) \
+	__i915_add_request(req, true)
+#define i915_add_request_no_flush(req) \
+	__i915_add_request(req, false)
+
+struct intel_rps_client;
+#define NO_WAITBOOST ERR_PTR(-1)
+#define IS_RPS_CLIENT(p) (!IS_ERR(p))
+#define IS_RPS_USER(p) (!IS_ERR_OR_NULL(p))
+
+int i915_wait_request(struct drm_i915_gem_request *req,
+		      unsigned int flags,
+		      s64 *timeout,
+		      struct intel_rps_client *rps)
+	__attribute__((nonnull(1)));
+#define I915_WAIT_INTERRUPTIBLE	BIT(0)
+#define I915_WAIT_LOCKED	BIT(1) /* struct_mutex held, handle GPU reset */
+
+static inline u32 intel_engine_get_seqno(struct intel_engine_cs *engine);
+
+/**
+ * Returns true if seq1 is later than seq2.
+ */
+static inline bool i915_seqno_passed(u32 seq1, u32 seq2)
+{
+	return (s32)(seq1 - seq2) >= 0;
+}
+
+static inline bool
+i915_gem_request_started(const struct drm_i915_gem_request *req)
+{
+	return i915_seqno_passed(intel_engine_get_seqno(req->engine),
+				 req->previous_seqno);
+}
+
+static inline bool
+i915_gem_request_completed(const struct drm_i915_gem_request *req)
+{
+	return i915_seqno_passed(intel_engine_get_seqno(req->engine),
+				 req->fence.seqno);
+}
+
+bool __i915_spin_request(const struct drm_i915_gem_request *request,
+			 int state, unsigned long timeout_us);
+static inline bool i915_spin_request(const struct drm_i915_gem_request *request,
+				     int state, unsigned long timeout_us)
+{
+	return (i915_gem_request_started(request) &&
+		__i915_spin_request(request, state, timeout_us));
+}
+
+/* We treat requests as fences. This is not be to confused with our
+ * "fence registers" but pipeline synchronisation objects ala GL_ARB_sync.
+ * We use the fences to synchronize access from the CPU with activity on the
+ * GPU, for example, we should not rewrite an object's PTE whilst the GPU
+ * is reading them. We also track fences at a higher level to provide
+ * implicit synchronisation around GEM objects, e.g. set-domain will wait
+ * for outstanding GPU rendering before marking the object ready for CPU
+ * access, or a pageflip will wait until the GPU is complete before showing
+ * the frame on the scanout.
+ *
+ * In order to use a fence, the object must track the fence it needs to
+ * serialise with. For example, GEM objects want to track both read and
+ * write access so that we can perform concurrent read operations between
+ * the CPU and GPU engines, as well as waiting for all rendering to
+ * complete, or waiting for the last GPU user of a "fence register". The
+ * object then embeds a #i915_gem_active to track the most recent (in
+ * retirement order) request relevant for the desired mode of access.
+ * The #i915_gem_active is updated with i915_gem_active_set() to track the
+ * most recent fence request, typically this is done as part of
+ * i915_vma_move_to_active().
+ *
+ * When the #i915_gem_active completes (is retired), it will
+ * signal its completion to the owner through a callback as well as mark
+ * itself as idle (i915_gem_active.request == NULL). The owner
+ * can then perform any action, such as delayed freeing of an active
+ * resource including itself.
+ */
+struct i915_gem_active;
+
+typedef void (*i915_gem_retire_fn)(struct i915_gem_active *,
+				   struct drm_i915_gem_request *);
+
+struct i915_gem_active {
+	struct drm_i915_gem_request __rcu *request;
+	struct list_head link;
+	i915_gem_retire_fn retire;
+};
+
+void i915_gem_retire_noop(struct i915_gem_active *,
+			  struct drm_i915_gem_request *request);
+
+/**
+ * init_request_active - prepares the activity tracker for use
+ * @active - the active tracker
+ * @func - a callback when then the tracker is retired (becomes idle),
+ *         can be NULL
+ *
+ * init_request_active() prepares the embedded @active struct for use as
+ * an activity tracker, that is for tracking the last known active request
+ * associated with it. When the last request becomes idle, when it is retired
+ * after completion, the optional callback @func is invoked.
+ */
+static inline void
+init_request_active(struct i915_gem_active *active,
+		    i915_gem_retire_fn retire)
+{
+	INIT_LIST_HEAD(&active->link);
+	active->retire = retire ?: i915_gem_retire_noop;
+}
+
+/**
+ * i915_gem_active_set - updates the tracker to watch the current request
+ * @active - the active tracker
+ * @request - the request to watch
+ *
+ * i915_gem_active_set() watches the given @request for completion. Whilst
+ * that @request is busy, the @active reports busy. When that @request is
+ * retired, the @active tracker is updated to report idle.
+ */
+static inline void
+i915_gem_active_set(struct i915_gem_active *active,
+		    struct drm_i915_gem_request *request)
+{
+	list_move(&active->link, &request->active_list);
+	rcu_assign_pointer(active->request, request);
+}
+
+static inline struct drm_i915_gem_request *
+__i915_gem_active_peek(const struct i915_gem_active *active)
+{
+	/* Inside the error capture (running with the driver in an unknown
+	 * state), we want to bend the rules slightly (a lot).
+	 *
+	 * Work is in progress to make it safer, in the meantime this keeps
+	 * the known issue from spamming the logs.
+	 */
+	return rcu_dereference_protected(active->request, 1);
+}
+
+/**
+ * i915_gem_active_raw - return the active request
+ * @active - the active tracker
+ *
+ * i915_gem_active_raw() returns the current request being tracked, or NULL.
+ * It does not obtain a reference on the request for the caller, so the caller
+ * must hold struct_mutex.
+ */
+static inline struct drm_i915_gem_request *
+i915_gem_active_raw(const struct i915_gem_active *active, struct mutex *mutex)
+{
+	return rcu_dereference_protected(active->request,
+					 lockdep_is_held(mutex));
+}
+
+/**
+ * i915_gem_active_peek - report the active request being monitored
+ * @active - the active tracker
+ *
+ * i915_gem_active_peek() returns the current request being tracked if
+ * still active, or NULL. It does not obtain a reference on the request
+ * for the caller, so the caller must hold struct_mutex.
+ */
+static inline struct drm_i915_gem_request *
+i915_gem_active_peek(const struct i915_gem_active *active, struct mutex *mutex)
+{
+	struct drm_i915_gem_request *request;
+
+	request = i915_gem_active_raw(active, mutex);
+	if (!request || i915_gem_request_completed(request))
+		return NULL;
+
+	return request;
+}
+
+/**
+ * i915_gem_active_get - return a reference to the active request
+ * @active - the active tracker
+ *
+ * i915_gem_active_get() returns a reference to the active request, or NULL
+ * if the active tracker is idle. The caller must hold struct_mutex.
+ */
+static inline struct drm_i915_gem_request *
+i915_gem_active_get(const struct i915_gem_active *active, struct mutex *mutex)
+{
+	return i915_gem_request_get(i915_gem_active_peek(active, mutex));
+}
+
+/**
+ * __i915_gem_active_get_rcu - return a reference to the active request
+ * @active - the active tracker
+ *
+ * __i915_gem_active_get() returns a reference to the active request, or NULL
+ * if the active tracker is idle. The caller must hold the RCU read lock, but
+ * the returned pointer is safe to use outside of RCU.
+ */
+static inline struct drm_i915_gem_request *
+__i915_gem_active_get_rcu(const struct i915_gem_active *active)
+{
+	/* Performing a lockless retrieval of the active request is super
+	 * tricky. SLAB_DESTROY_BY_RCU merely guarantees that the backing
+	 * slab of request objects will not be freed whilst we hold the
+	 * RCU read lock. It does not guarantee that the request itself
+	 * will not be freed and then *reused*. Viz,
+	 *
+	 * Thread A			Thread B
+	 *
+	 * req = active.request
+	 *				retire(req) -> free(req);
+	 *				(req is now first on the slab freelist)
+	 *				active.request = NULL
+	 *
+	 *				req = new submission on a new object
+	 * ref(req)
+	 *
+	 * To prevent the request from being reused whilst the caller
+	 * uses it, we take a reference like normal. Whilst acquiring
+	 * the reference we check that it is not in a destroyed state
+	 * (refcnt == 0). That prevents the request being reallocated
+	 * whilst the caller holds on to it. To check that the request
+	 * was not reallocated as we acquired the reference we have to
+	 * check that our request remains the active request across
+	 * the lookup, in the same manner as a seqlock. The visibility
+	 * of the pointer versus the reference counting is controlled
+	 * by using RCU barriers (rcu_dereference and rcu_assign_pointer).
+	 *
+	 * In the middle of all that, we inspect whether the request is
+	 * complete. Retiring is lazy so the request may be completed long
+	 * before the active tracker is updated. Querying whether the
+	 * request is complete is far cheaper (as it involves no locked
+	 * instructions setting cachelines to exclusive) than acquiring
+	 * the reference, so we do it first. The RCU read lock ensures the
+	 * pointer dereference is valid, but does not ensure that the
+	 * seqno nor HWS is the right one! However, if the request was
+	 * reallocated, that means the active tracker's request was complete.
+	 * If the new request is also complete, then both are and we can
+	 * just report the active tracker is idle. If the new request is
+	 * incomplete, then we acquire a reference on it and check that
+	 * it remained the active request.
+	 *
+	 * It is then imperative that we do not zero the request on
+	 * reallocation, so that we can chase the dangling pointers!
+	 * See i915_gem_request_alloc().
+	 */
+	do {
+		struct drm_i915_gem_request *request;
+
+		request = rcu_dereference(active->request);
+		if (!request || i915_gem_request_completed(request))
+			return NULL;
+
+		/* An especially silly compiler could decide to recompute the
+		 * result of i915_gem_request_completed, more specifically
+		 * re-emit the load for request->fence.seqno. A race would catch
+		 * a later seqno value, which could flip the result from true to
+		 * false. Which means part of the instructions below might not
+		 * be executed, while later on instructions are executed. Due to
+		 * barriers within the refcounting the inconsistency can't reach
+		 * past the call to i915_gem_request_get_rcu, but not executing
+		 * that while still executing i915_gem_request_put() creates
+		 * havoc enough.  Prevent this with a compiler barrier.
+		 */
+		barrier();
+
+		request = i915_gem_request_get_rcu(request);
+
+		/* What stops the following rcu_access_pointer() from occurring
+		 * before the above i915_gem_request_get_rcu()? If we were
+		 * to read the value before pausing to get the reference to
+		 * the request, we may not notice a change in the active
+		 * tracker.
+		 *
+		 * The rcu_access_pointer() is a mere compiler barrier, which
+		 * means both the CPU and compiler are free to perform the
+		 * memory read without constraint. The compiler only has to
+		 * ensure that any operations after the rcu_access_pointer()
+		 * occur afterwards in program order. This means the read may
+		 * be performed earlier by an out-of-order CPU, or adventurous
+		 * compiler.
+		 *
+		 * The atomic operation at the heart of
+		 * i915_gem_request_get_rcu(), see fence_get_rcu(), is
+		 * atomic_inc_not_zero() which is only a full memory barrier
+		 * when successful. That is, if i915_gem_request_get_rcu()
+		 * returns the request (and so with the reference counted
+		 * incremented) then the following read for rcu_access_pointer()
+		 * must occur after the atomic operation and so confirm
+		 * that this request is the one currently being tracked.
+		 *
+		 * The corresponding write barrier is part of
+		 * rcu_assign_pointer().
+		 */
+		if (!request || request == rcu_access_pointer(active->request))
+			return rcu_pointer_handoff(request);
+
+		i915_gem_request_put(request);
+	} while (1);
+}
+
+/**
+ * i915_gem_active_get_unlocked - return a reference to the active request
+ * @active - the active tracker
+ *
+ * i915_gem_active_get_unlocked() returns a reference to the active request,
+ * or NULL if the active tracker is idle. The reference is obtained under RCU,
+ * so no locking is required by the caller.
+ *
+ * The reference should be freed with i915_gem_request_put().
+ */
+static inline struct drm_i915_gem_request *
+i915_gem_active_get_unlocked(const struct i915_gem_active *active)
+{
+	struct drm_i915_gem_request *request;
+
+	rcu_read_lock();
+	request = __i915_gem_active_get_rcu(active);
+	rcu_read_unlock();
+
+	return request;
+}
+
+/**
+ * i915_gem_active_isset - report whether the active tracker is assigned
+ * @active - the active tracker
+ *
+ * i915_gem_active_isset() returns true if the active tracker is currently
+ * assigned to a request. Due to the lazy retiring, that request may be idle
+ * and this may report stale information.
+ */
+static inline bool
+i915_gem_active_isset(const struct i915_gem_active *active)
+{
+	return rcu_access_pointer(active->request);
+}
+
+/**
+ * i915_gem_active_is_idle - report whether the active tracker is idle
+ * @active - the active tracker
+ *
+ * i915_gem_active_is_idle() returns true if the active tracker is currently
+ * unassigned or if the request is complete (but not yet retired). Requires
+ * the caller to hold struct_mutex (but that can be relaxed if desired).
+ */
+static inline bool
+i915_gem_active_is_idle(const struct i915_gem_active *active,
+			struct mutex *mutex)
+{
+	return !i915_gem_active_peek(active, mutex);
+}
+
+/**
+ * i915_gem_active_wait - waits until the request is completed
+ * @active - the active request on which to wait
+ *
+ * i915_gem_active_wait() waits until the request is completed before
+ * returning. Note that it does not guarantee that the request is
+ * retired first, see i915_gem_active_retire().
+ *
+ * i915_gem_active_wait() returns immediately if the active
+ * request is already complete.
+ */
+static inline int __must_check
+i915_gem_active_wait(const struct i915_gem_active *active, struct mutex *mutex)
+{
+	struct drm_i915_gem_request *request;
+
+	request = i915_gem_active_peek(active, mutex);
+	if (!request)
+		return 0;
+
+	return i915_wait_request(request,
+				 I915_WAIT_INTERRUPTIBLE | I915_WAIT_LOCKED,
+				 NULL, NULL);
+}
+
+/**
+ * i915_gem_active_wait_unlocked - waits until the request is completed
+ * @active - the active request on which to wait
+ * @flags - how to wait
+ * @timeout - how long to wait at most
+ * @rps - userspace client to charge for a waitboost
+ *
+ * i915_gem_active_wait_unlocked() waits until the request is completed before
+ * returning, without requiring any locks to be held. Note that it does not
+ * retire any requests before returning.
+ *
+ * This function relies on RCU in order to acquire the reference to the active
+ * request without holding any locks. See __i915_gem_active_get_rcu() for the
+ * glory details on how that is managed. Once the reference is acquired, we
+ * can then wait upon the request, and afterwards release our reference,
+ * free of any locking.
+ *
+ * This function wraps i915_wait_request(), see it for the full details on
+ * the arguments.
+ *
+ * Returns 0 if successful, or a negative error code.
+ */
+static inline int
+i915_gem_active_wait_unlocked(const struct i915_gem_active *active,
+			      unsigned int flags,
+			      s64 *timeout,
+			      struct intel_rps_client *rps)
+{
+	struct drm_i915_gem_request *request;
+	int ret = 0;
+
+	request = i915_gem_active_get_unlocked(active);
+	if (request) {
+		ret = i915_wait_request(request, flags, timeout, rps);
+		i915_gem_request_put(request);
+	}
+
+	return ret;
+}
+
+/**
+ * i915_gem_active_retire - waits until the request is retired
+ * @active - the active request on which to wait
+ *
+ * i915_gem_active_retire() waits until the request is completed,
+ * and then ensures that at least the retirement handler for this
+ * @active tracker is called before returning. If the @active
+ * tracker is idle, the function returns immediately.
+ */
+static inline int __must_check
+i915_gem_active_retire(struct i915_gem_active *active,
+		       struct mutex *mutex)
+{
+	struct drm_i915_gem_request *request;
+	int ret;
+
+	request = i915_gem_active_raw(active, mutex);
+	if (!request)
+		return 0;
+
+	ret = i915_wait_request(request,
+				I915_WAIT_INTERRUPTIBLE | I915_WAIT_LOCKED,
+				NULL, NULL);
+	if (ret)
+		return ret;
+
+	list_del_init(&active->link);
+	RCU_INIT_POINTER(active->request, NULL);
+
+	active->retire(active, request);
+
+	return 0;
+}
+
+/* Convenience functions for peeking at state inside active's request whilst
+ * guarded by the struct_mutex.
+ */
+
+static inline uint32_t
+i915_gem_active_get_seqno(const struct i915_gem_active *active,
+			  struct mutex *mutex)
+{
+	return i915_gem_request_get_seqno(i915_gem_active_peek(active, mutex));
+}
+
+static inline struct intel_engine_cs *
+i915_gem_active_get_engine(const struct i915_gem_active *active,
+			   struct mutex *mutex)
+{
+	return i915_gem_request_get_engine(i915_gem_active_peek(active, mutex));
+}
+
+#define for_each_active(mask, idx) \
+	for (; mask ? idx = ffs(mask) - 1, 1 : 0; mask &= ~BIT(idx))
+
+#endif /* I915_GEM_REQUEST_H */